1. Field of the Invention
This invention describes a storm drain protector used to filter storm water runoff of sediment and other debris so that such materials do not clog the drain, hinder flow or pollute the body of water to which such drains ultimately flow.
2. Description of Related Art
Storm drains, commonly located in roadways, parking lots or beside sidewalks, are ordinarily covered by a simple metal grating that serves the dual purpose of preventing large debris from entering the drain and providing a barrier for pedestrians and animals. Such a grating does not filter anything but the largest of debris and is easily clogged when such large materials amass and cover the opening. Where there is a potential for large amounts of sediment or debris being washed into the drain, such as near a construction site, there exists a need for additional protection and filtration for the storm drain. This need is augmented by the fact that runoff water is often directly channeled to the ocean or other public bodies of water. Public safety and recent environmental regulation prohibiting the contamination of such resources, now requires that water entering storm drains not be polluted.
Numerous products have been used to prevent sediment or other materials from flowing into storm drains in such situations. U.S. Pat. No. 7,481,921, granted to Kent on Jan. 27, 2009, discloses a cleanable and reusable fibrous mat adapted to filter water that is placed over the top of a preexisting grating on a storm drain. Unfortunately, storm drains are subject to variable flow rates, with very high rates being common. Although the Kent apparatus succeeds in preventing the passage of sediment and small debris that would otherwise bypass the grating, it is likely that such a fibrous mat would need to be continuously cleaned and would quickly clog in high flow situations or if left untended for any significant period of time. Moreover, the Kent apparatus provides no method of filtering liquid contaminants, such as motor oil, that may commonly find their way to storm drains.
Another type of storm drain filter device is disclosed in U.S. Pat. No. 7,156,987, issued to Sanguinetti on Jan. 2, 2007. Sanguinetti describes a flexible, frameless filter bag. In this system, the metal storm drain grating is removed and placed into a filter bag capable of filtering in-flowing water. The grating, now wrapped in the bag, is then placed back into the drain. The bag is removed and emptied when it becomes filled with silt and debris. While the Sanguinetti device addresses the need to make such devices easily cleaned and installed, as with Kent, the Sanguinetti device has the disadvantage that it quickly becomes clogged and must be continuously cleaned to maintain flow into the drain. Kent also does not address the problem of potential liquid pollutants.
As is shown by the foregoing art, despite a long felt need, none of the prior approaches to preventing sediment and debris from entering storm drains have been able to effectively filter such materials in a way that prevents the filtering apparatus from quickly becoming clogged in high flow situations. Moreover, none of the prior approaches has been effective in substantially preventing liquid pollutants, such as motor oil, from passing into storm drains.